For example, Patent Literature 1 describes a conventional refrigeration apparatus of this type. According to the conventional refrigeration apparatus, a controller starts a compressor (high-temperature side compressor) constituting a primary side refrigerant circuit based on an internal temperature of a freezer output from a temperature sensor during a normal operation, and then starts a compressor (low-temperature side compressor) of a secondary side refrigerant circuit after an elapse of a predetermined time. When the internal temperature reaches an upper limit of a target value, the controller initially starts the primary side refrigerant circuit including the high-temperature side compressor based on output from the temperature sensor which detects the internal temperature. Thereafter, the controller opens an electromagnetic valve provided between the compressor and an evaporator in the secondary side refrigerant circuit, and starts the low-temperature side compressor. Thereafter, the controller executes such control as to open an electromagnetic valve provided between a cascade condenser and an expander in the secondary side refrigerant circuit.